Repainting metal patio furniture via blog: 1)use wire brush/sandpaper to get off loose paint/rust, 2)wash/wipe down and dry, 3)prime, 4)paint with spray paint designed for metal. Blog suggests Rust-oleum paint throughout.
Using a drill or screw driver, remove the cushions from your chairs. Wipe chairs clean, spray paint your chairs and let them dry 24 hours. Cover you cushion in fabric and wrap it around onto the backside. Use a staple gun or a strong adhesive to secure the fabric on the back. Screw your cushions back onto your chairs.